New Study Strengthens Link Between Obesity, Diabetes and BPA

There's more reason to steer clear of Bisphenol A (BPA) than its now-notorious link to cancer and other health problems; and the risks it poses especially for children. Now, a recent study provides evidence that BPA also contributes to obesity and insulin resistance, which can lead to diabetes.

To some people, this may not sound like news, but the study, published in PLoS ONE, pinpoints just how this works, an understanding that was lacking before.

Insulin Overload

The study found that BPA triggers the release of insulin in nearly twice the amount as when glucose is ingested—and high insulin levels can lead to insulin resistance and potentially to weight gain and Type 2 diabetes.

To achieve this feat, BPA fools a receptor into thinking it is the natural hormone estrogen, an insulin regulator. Nadal's team found that even the tiniest amounts of BPA -- a quarter of a billionth of a gram -- did the trick. The effect disappeared when the researchers stripped the specific receptors from the study mice, evidence that they had in fact pinpointed BPA's chemical mechanism, which had previously eluded scientists.

Found both in and outside of our food supply, BPA often seems like it's everywhere and impossible to avoid. It's important to remember that BPA is not the only problem we face—but it's something that does present clear risks, and the link with obesity and diabetes is just another reason to avoid it when possible.

"When you eat something with BPA, it's like telling your organs that you are eating more than you are really eating," says Angel Nadal, a BPA expert at the Miguel Hernendez University in Spain...

An estimated 90 percent of people in developed countries have BPA circulating in their blood at levels often higher than the threshold for causing hormone disruption used in Nadal's study. This high incidence is due not only to exposures from leeching food packages but also BPA-infused cash register receipts, dental sealants and toilet paper.

"People are seeing effects of BPA down to 1000-fold below [Nadal's threshold]," adds Frederick vom Saal, another expert in endocrine disruptors at the University of Missouri-Columbia. "It takes so little of this chemical to cause harm."